The manufacture of fiber-reinforced three-dimensional parts is typically accomplished by one of two methods: master tooling; or "contact lay-up." The master tooling method includes the fabrication of a solid pattern typically of wood or metal via a multi-step tooling process. This method of tooling is not employed often due to the craftsmanship skills and experience needed to work with a solid wood or metal pattern.
Generally, the contact lay-up method of tooling includes the steps of: (1) fabricating a tool; (2) applying resin-wetted layers of fiber material to the tool; (3) curing the fiber layers; (4) removing the tool; and (5) trimming and cleaning the part. The primary disadvantage of this method of tooling is the amount of time and expense incurred to fabricate the tool. Manufacture of a single three-dimensional part by this method requires a minimum of three intermediate tools. If the part to be manufactured includes negative draft angles or other complex shaping requirements, more than three intermediate tools may be required. Additionally, design changes are difficult to incorporate. Finally, human error, storage and maintenance requirements, and labor-intensive in-processing severely limit this method.
Thus a need has arisen for a manufacturing method whereby fiber-reinforced three-dimensional parts are created utilizing a single-tool process, thereby minimizing material, time and labor resources while offering greater flexibility and accuracy.